Method for detecting wheel imbalances in a vehicle

Patent metadata

Field	Value
Publication number	US-10156492-B2
Application number	US-201615554672-A
Country	US
Kind code	B2
Filing date	Jan 15, 2016
Priority date	Mar 6, 2015
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

In a method for detecting wheel imbalances in a vehicle, the profile of the driving state variable is ascertained by sensor over a speed range of the vehicle; a frequency analysis is performed; and a resonance step-up is indicative of a wheel imbalance.

First claim

What is claimed is:

1. A method comprising:
ascertaining a driving state variable by a sensor over a speed range of a vehicle;
performing a frequency analysis of the driving state variable, thereby obtaining for each of a plurality of speeds of the speed range a respective one of a plurality of frequency values;
analyzing the plurality of frequency values to identify a step-up in the plurality of frequency values within the speed range;
comparing a peak one of the frequency values of the identified step-up to a single threshold value applied to the plurality of speeds of the speed range; and
determining whether there is a wheel imbalance of a wheel of the vehicle based on a result of the comparison.

2. The method of claim 1 , wherein the sensor is part of a sensor system of an electronic stability program in the vehicle.

3. The method of claim 1 , further comprising outputting a warning signal in response to the wheel imbalance being determined to be present in the determining step, wherein the wheel imbalance is determined to be present in the determining step when the peak one of the plurality of frequency values of the identified step-up exceeds the threshold value.

4. The method of claim 3 , wherein the warning signal is signaled in the vehicle.

5. The method of claim 3 , wherein the warning signal is wirelessly transmitted from the vehicle to a reception point outside of the vehicle.

6. The method of claim 5 , wherein the warning signal is transmitted to the reception point via an external device that is connected in the vehicle.

7. The method of claim 1 , wherein signals from at least one further sensor are evaluated to determine the imbalance.

8. The method of claim 1 , wherein the frequency analysis is only performed if the vehicle speed reaches a speed-limiting value.

9. A control unit, comprising:
a control device configured to perform the following:
ascertain, based on output of a sensor, a driving state variable over a speed range of a vehicle;
perform a frequency analysis of the driving state variable, thereby obtaining for each of a plurality of speeds of the speed range a respective one of a plurality of frequency values;
analyze the plurality of frequency values to identify a step-up in the plurality of frequency values within the speed range;
compare a peak one of the frequency values of the identified step-up to a single threshold value applied to the plurality of speeds of the speed range; and
determine whether there is a wheel imbalance of a wheel of the vehicle based on a result of the comparison.

10. A vehicle, comprising:
at least one wheel-speed sensor; and
a control device configured to perform the following:
ascertain, based on output of the at least one sensor, a driving state variable over a speed range of a vehicle;
perform a frequency analysis of the driving state variable, thereby obtaining for each of a plurality of speeds of the speed range a respective one of a plurality of frequency values;
analyze the plurality of frequency values to identify a step-up in the plurality of frequency values within the speed range;
compare a peak one of the frequency values of the identified step-up to a single threshold value applied to the plurality of speeds of the speed range; and
determine whether there is a wheel imbalance of a wheel of the vehicle based on a result of the comparison.

11. The method of claim 3 , wherein the warning signal is wirelessly transmitted from the vehicle to a reception point outside of the vehicle to a repair shop.

12. The method of claim 5 , wherein the warning signal is transmitted to the reception point that is outside of the vehicle via a smart phone that is connected in the vehicle.

13. The method of claim 1 , wherein signals, which are vehicle accelerations, from at least one further sensor are also evaluated to determine the imbalance.

14. The method of claim 1 , wherein the speed range for the plurality of speeds of which the plurality of frequency values used for the determining are obtained is a predefined limited speed range, frequency values of the driving state variable corresponding to speeds out of the speed range being ignored in at least one of the ascertaining, performing, and analyzing steps.

Assignees

• Bosch Gmbh Robert

Inventors

• Scheuing Jan
• Martin Uwe

Classifications

• G01M1/28

  with special adaptations for determining imbalance of the body in situ, e.g. of vehicle wheels · CPC title

• A61B2562/0219

  Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches · CPC title

• G01M1/225 Primary

  for vehicle wheels (in situ G01M1/28) · CPC title

• G01M17/013

  Wheels · CPC title